在普略纪中期的温暖时期,近地表永久土的高度限制范围
Donglin Guo1,2, Huijun Wang2, Vladimir E Romanovsky3,4
1Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
概括
在普略世中期的温暖时期,永久土的面积减少了93%. 这个古老的温暖时期为未来的永久土变化和气候变化影响提供了洞察力.
科学领域:
- 古气候学 古气候学
- 永久土科学 永久土科学
- 气候建模气候模型
背景情况:
- 准确预测未来的永久土动态对于评估气候变化影响至关重要,但目前的模型面临着重大不确定性.
- 研究过去的温暖时期,比如普略纪中期的温暖时期 (mPWP),为未来的永久土行为提供了有价值的类比,并有助于减少预测的不确定性.
研究的目的:
- 在mPWP期间模拟近地表永久土的延伸,使用地表冰指数模型和二代模型对比项目输出.
- 为了将mPWP永久土条件与在高排放场景下预测的未来永久土变化进行比较.
主要方法:
- 结合了表面冰指数模型和气候模型输出,从二世模型对比项目第二阶段.
- 在北半球mPWP (~3.264到3.025万年前) 期间模拟的近地表 (~3-4米深) 永久土分布.
- 使用基于代理的表面空气温度记录的受限模拟.
主要成果:
- 在mPWP期间,近地表永久土比工业化前的范围小了93±3%.
- 永久土在空间上受限于特定的高度地区:西伯利亚东部高地,加拿大高北极群岛和格陵兰最北端.
- 模拟的mPWP永久土范围与SSP5-8.5情景下21世纪末的预测非常相似.
结论:
- 在未来更温暖的世界里,mPWP作为理解潜在的永久土降解的相关类比.
- 模拟突出了在持续变暖下,近地表永久土范围的显著潜在减少.
- 这项研究增强了我们对永久土对气候变化敏感性的理解,并改进了未来的预测.
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